1. Field of the Invention
The present disclosure relates to a device in the technology field of film coating, more specifically, to an upper electrode device.
2. Description of the Related Art
In the related art of film coating, the upper electrode device in the gas diffusion system on the process machine generally comprises the gas diversion plate which is a three-layers structure. FIG. 1A shows a side view of the upper electrode device in the related art; FIG. 1B shows a vertical view of the upper electrode device in the related art. As shown in FIG. 1A, the upper electrode device comprises three gas diversion plates. From the top to the bottom, there is First Gas Diversion Plate 1′, Second Gas Diversion Plate 2′ and Third Gas Diversion Plate 3′ in sequence, and hole(s) with the same size were formed on the surface of each gas diversion plate. As shown in FIGS. 1A and 1B, the holes were distributed in forms of matrix on the surface of each gas diversion plate. Holes 41′ on the surface of First Gas Diversion Plate 1′ was vertically staggered from Holes 42′ on the surface of Second Gas Diversion Plate 2′. Likewise, Holes 42′ on the surface of Second Gas Diversion Plate 2′ was vertically staggered from Holes 43′ formed on the surface of Third Gas Diversion Plate 3′. To some extent, the upper electrode device can divert the gas and makes the film coated more uniform, but in the actual process of coating film, effect of the gas diversion is not ideal. When the gas was diverted into the lowest layer during the process of film coating, the gas near the centre part is sufficient but the gas near the edge or the corners is insufficient, which causes that the thickness of the film coated is not uniform, i.e., the thickness in the center area of the film coated is thick and the thickness in the edge of the film coated is thin. Consequently, the performance of the device is low.
A related art has provided a sputtering coating equipment for improving the uniformity of the film, which comprises a square air inlet pipe and a round air inlet pipe. Twenty-two gas spray nozzles are installed on the surface of the square air inlet pipe, which faces to a target, and three hanging pieces are installed above the square air inlet pipe and used for fixing the whole air inlet device. The sputtering coating equipment is used for solving the problem that the thickness of the film coated by the device is uneven because of an uneven air supply device in the related art. However, the multiple gas spray nozzles cause a complicated structure of the device, and it is not easy to control the consistency between the gas spray nozzles. Hence, it is not easy to be applied in the actual manufacturing processes.
Another related art provides a coating device for a dispersion plate which is used for the dispersion of gas. The coating device comprises a hollow type shell body provided with a coating chamber, an electrode unit with a plurality of electrode plates which are separated arranged inside the coating chamber, a gas delivery pipe which delivers the coating gas into the coating chamber of the shell body, a suction unit of a pump which is communicated with the coating chamber, and a dispersion plate with a plurality of relief holes which are separated and close to the bottom side of the electrode plate. The relief holes are arranged on the most area of the bottom side of the electrode plate. With the relief holes, the coating gas can be uniformly distributed on the coating chamber, so the coating yield is increased and the overall coating efficiency is improved. Although the film coating device disclosed in this patent has the effect to disperse the gas, it did not relate to promoting the uniformity of the film at the area of the edges and the corners after the gas was dispersed.
Hence, there is no effective solution for solving the problem in the related arts.